1. Field of the Invention
This invention relates to a metal saw cutter for pipes, rods, bars, or the like, and, in particular to a control apparatus for the metal saw cutter.
This invention particularly relates to a metal saw cutter for cutting or grooving a workpiece, such as a pipe or the like, while rotating the workpiece during cutting by a metal saw.
2. Description of the Prior Art
In gas supply piping or water supply piping, steel pipes coated with a plastic layer, such as polyethylene, on the inner surface and/or the outer surface of the pipe for protection against erosion, and the like, are used.
Usually, a roller cutter is used to cut such a plastic-coated pipe. However, a roller cutter causes the production of burrs or flapping of the plastic layer at the cutting surface of the workpiece, with the result that it fails to produce a clean cutting surface. Conversely, a metal saw is known to be free from the production of such burrs or flapping of the plastic layer.
The present invention, therefore, provides a cutter using a metal saw which can provide a good cutting surface. Usually, in cutting with a metal saw, the workpiece is fixed and does not rotate, i.e., only the metal saw rotates. In other words, a metal saw cutter in which both the metal saw and the workpiece rotate did not exist before the present invention. Therefore, in the prior art, when the fixed workpiece, e.g., a pipe, has a large diameter, a large diameter metal saw must be used. This results in the necessity to use a large size metal saw cutter, and also results in a large consumption of electric power for driving the metal saw.